When a user calls a call center, a call routing system that handles incoming calls may attempt to connect the user to one of multiple agents attending the call center. However, the attempt to connect to the agent may fail for a variety of reasons. For example, the call may be forwarded to a non-existing business group, the attempt to extend the call may be blocked, a server receiving the call may fail (e.g., when the call is voice-over-Internet Protocol (VoIP), etc.